我有如下数据:

PID SID CID Price
1   1   1   18
2   1   1   19
3   1   2   10
4   2   2   22
5   2   2   21.35
6   3   2   25
7   3   7   30
8   3   2   40


我想为CID最小且价格最大的每个SID选择行。

预期产量:

PID SID CID Price
2   1   1   19
4   2   2   22
8   3   2   40


我的查询给出了预期的输出。但是由于我是MySQL的新手,所以我不确定这是否是最佳的实现方法。

查询:

select a.PID, a.SID, a.CID, a.Price
from Products a
inner join (select SID as SID, min(CID) as CID_Min, max(Price) as Price_Max
            from Products
            group by SID) b
on a.SID=b.SID and
   a.CID=b.CID_Min and
   a.Price=b.Price_Max;


编辑#1:
抱歉,但我观察到如下数据集,该查询未返回任何输出:

PID SID CID Price
11  6   1   18
12  6   1   19
13  6   2   30


但是,预期输出为:

PID SID CID Price
11  6   1   19


由于SID = 6的最小CID为1,并且从值SID = 6和CID = 1,价格的最大值为19。

任何想法如何实现它。

此查询是否最佳:

select t.SID, t.CID, t.Price
from Products t
inner join
  (select p.SID as SID_max, p.CID as CID_max, max(p.Price) as Price_max
   from Products p
   inner join
     (select SID as SID_min, min(CID) as CID_min
      from Products
      group by SID) p_min
   on p.SID=p_min.SID_min and
      p.CID=p_min.CID_min
   group by p.SID, p.CID
  ) p_max
on t.SID=p_max.SID_max and
   t.CID=p_max.CID_max and
   t.Price=p_max.Price_max

最佳答案

您肯定要12、6、1、19!?!?!?!!?!?!?!

SELECT a.*
  FROM my_table a
  JOIN
     ( SELECT x.sid
            , x.cid
            , MAX(price) price
         FROM my_table x
         JOIN
            ( SELECT sid
                   , MIN(cid) cid
                FROM my_table
               GROUP
                  BY sid
            ) y
           ON y.sid = x.sid
          AND y.cid = x.cid
        GROUP
           BY sid
            , cid
     ) b
    ON b.sid = a.sid
   AND b.cid = a.cid
   AND b.price = a.price;
+-----+-----+-----+-------+
| pid | sid | cid | price |
+-----+-----+-----+-------+
|  12 |   6 |   1 |    19 |
+-----+-----+-----+-------+

关于mysql - 选择一列的最小值,另一列的最大值,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/49323823/

10-16 09:46